Processes for the production of hydrogenated products

ABSTRACT

A process for making a hydrogenated product includes providing a clarified DAS-containing fermentation broth, distilling the broth to form an overhead that includes water and ammonia, and a liquid bottoms that includes MAS, at least some DAS, and at least about 20 wt % water, cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS, separating the solid portion from the liquid portion, recovering the solid portion, hydrogenating the second solid portion in the presence of at least one hydrogenation catalyst to produce the hydrogenated product comprising at least one of THF, GBL or BDO, and recovering the hydrogenated product.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.13/051,688, filed Mar. 18, 2011, which claims the benefit of U.S.Provisional Application No. 61/320,074, filed Apr. 1, 2010, the subjectmatter of which is hereby incorporated by reference.

TECHNICAL FIELD

This disclosure relates to processes for producing hydrogenatedproducts, particularly 1,4-butanediol (BDO), tetrahydrofuran (THF), andgamma-butyrolactone (GBL) from succinic acid (SA) produced byfermentation.

BACKGROUND

Certain carbonaceous products of sugar fermentation are seen asreplacements for petroleum-derived materials for use as feedstocks forthe manufacture of carbon-containing chemicals. One such product is MAS.

A material related to MAS, namely SA, can be produced by microorganismsusing fermentable carbon sources such as sugars as starting materials.However, most commercially viable, succinate producing microorganismsdescribed in the literature neutralize the fermentation broth tomaintain an appropriate pH for maximum growth, conversion andproductivity. Typically, the pH of the fermentation broth is maintainedat or near a pH of 7 by introduction of ammonium hydroxide into thebroth, thereby converting the SA to DAS.

Kushiki (Japanese Published Patent Application, Publication No.2005-139156) discloses a method of obtaining MAS from an aqueoussolution of DAS that could be obtained from a fermentation broth towhich an ammonium salt is added as a counter ion. Specifically, MAS iscrystallized from an aqueous solution of DAS by adding acetic acid tothe solution to adjust the pH of the solution to a value between 4.6 and6.3, causing impure MAS to crystallize from the solution.

Masuda (Japanese Unexamined Application Publication P2007-254354, Oct.4, 2007) describes partial deammoniation of dilute aqueous solutions of“ammonium succinate” of the formula H₄NOOCCH₂CH₂COONH₄. From themolecular formula disclosed, it can be seen that “ammonium succinate” isdiammonium succinate. Masuda removes water and ammonia by heatingsolutions of the ammonium succinate to yield a solid SA-basedcomposition containing, in addition to ammonium succinate, at least oneof MAS, SA, monoamide succinate, succinimide, succinamide or estersuccinate. Thus, it can be inferred that like Kushiki, Masuda disclosesa process that results in production of impure MAS. The processes ofboth Kushiki and Masuda lead to materials that need to be subjected tovarious purification regimes to produce high purity MAS.

Bio-derived SA such as that derived from MAS is a platform molecule forsynthesis of a number of commercially important chemicals and polymers.Therefore, it is highly desirable to provide a purification technologythat offers flexibility to integrate clear, commercially viable paths toderivatives such as BDO, THF and GBL. In response to the lack of aneconomically and technically viable process solution for convertingfermentation-derived SA to BDO, THF, and GBL, it could be helpful toprovide methods for providing a cost effective SA stream of sufficientpurity for direct hydrogenation. Additionally, it is desirable toprovide methods for converting fermentation-derived MAS to BDO, THF, andGBL.

SUMMARY

We provide a process for making a hydrogenated product including (a)providing a clarified fermentation broth containing an ammonium salt ofsuccinic acid; (b) optionally adding at least one of MAS, DAS, SA, NH₃and NH₄ ⁺ to the broth depending on pH of the broth; (c) distilling thebroth to form an overhead that comprises water and optionally ammoniaand a liquid bottoms that comprises MAS, at least some DAS, and at leastabout 20 wt % water; (d) cooling and/or evaporating the bottoms, andoptionally adding an antisolvent to the bottoms, to attain a temperatureand composition sufficient to cause the bottoms to separate into aDAS-containing liquid portion and a MAS-containing solid portion that issubstantially free of DAS; (e) separating the solid portion from theliquid portion; (f) recovering the solid portion; (g) hydrogenating thesolid portion in the presence of at least one hydrogenation catalyst toproduce the hydrogenated product comprising at least one of THF, GBL orBDO; and (h) recovering the hydrogenated product.

We also provide a process for making a hydrogenated product includingproviding a clarified DAS-containing fermentation broth, distilling thebroth to form a first overhead that comprises water and ammonia, and afirst liquid bottoms that comprises MAS, at least some DAS, and at leastabout 20 wt % water, cooling and/or evaporating the first bottoms, andoptionally adding an antisolvent to the bottoms, to attain a temperatureand composition sufficient to cause the first bottoms to separate into aDAS-containing liquid portion and a MAS-containing first solid portionthat is substantially free of DAS, separating the first solid portionfrom the first liquid portion, recovering the first solid portion,dissolving the first solid portion in water to produce an aqueous MASsolution, distilling the aqueous MAS solution at a temperature andpressure sufficient to form a second overhead that comprises water andammonia, and a second bottoms that comprises a major portion of SA, aminor portion of MAS, and water, cooling the second bottoms to cause thesecond bottoms to separate into a second liquid portion in contact witha second solid portion that consists essentially of SA and issubstantially free of MAS, separating the second solid portion from thesecond liquid portion, recovering the second solid portion,hydrogenating the second solid portion in the presence of at least onehydrogenation catalyst to produce the hydrogenated product comprising atleast one of THF, GBL or BDO, and recovering the hydrogenated product.

We further provide a process for making a hydrogenated product includingproviding a clarified SA-containing fermentation broth, optionally,adding at least one of MAS, DAS, SA, NH₃ and NH₄ ⁺ to the broth tomaintain the pH of the broth below 6, distilling the broth to form anoverhead that comprises water and ammonia, and a liquid bottoms thatincludes MAS, at least some DAS, and at least about 20 wt % water,cooling and/or evaporating the bottoms, and optionally adding anantisolvent to the bottoms, to attain a temperature and compositionsufficient to cause the bottoms to separate into a DAS-containing liquidportion and a MAS-containing solid portion that is substantially free ofDAS, separating the solid portion from the liquid portion, recoveringthe solid portion, dissolving the solid portion in water to produce anaqueous MAS solution, distilling the aqueous MAS solution at atemperature and pressure sufficient to form a second overhead thatcomprises water and ammonia, and a second bottoms that comprises a majorportion of SA, a minor portion of MAS, and water, cooling and/orevaporating the second bottoms to cause the second bottoms to separateinto a second liquid portion and a second solid portion that consistsessentially of SA and is substantially free of MAS, separating thesecond solid portion from the second liquid portion, recovering thesecond solid portion, hydrogenating the second solid portion in thepresence of at least one hydrogenation catalyst to produce thehydrogenated product comprising at least one of THF, GBL or BDO, andrecovering the hydrogenated product.

We still further provide a process for a hydrogenated product includingproviding making a DAS-containing fermentation broth, distilling thebroth to form a first overhead that includes water and ammonia, and afirst liquid bottoms that includes MAS, at least some DAS, and at leastabout 20 wt % water, cooling and/or evaporating the bottoms, andoptionally adding an antisolvent to the bottoms, to attain a temperatureand composition sufficient to cause the bottoms to separate into aDAS-containing liquid portion and a MAS-containing solid portion that issubstantially free of DAS, separating the solid portion from the liquidportion, recovering the solid portion, dissolving the solid portion inwater to produce an aqueous MAS solution, distilling the aqueous MASsolution at a temperature and pressure sufficient to form a secondoverhead that includes water and ammonia, and a second bottoms thatincludes a major portion of SA, a minor portion of MAS, and water,cooling and/or evaporating the second bottoms to cause the secondbottoms to separate into a second liquid portion in contact with asecond solid portion that preferably consists essentially of SA and issubstantially free of MAS, separating the second solid portion from thesecond liquid portion, recovering the second solid portion,hydrogenating the second solid portion in the presence of at least onehydrogenation catalyst to produce the hydrogenated product comprising atleast one of THF, GBL or BDO, and recovering the hydrogenated product.

We yet further provide a process for making a hydrogenated productincluding providing a clarified MAS-containing broth, optionally, addingat least one of MAS, DAS, SA, NH₃ and NH₄ ⁺ to the broth to preferablymaintain the pH of the broth below 6, distilling the broth to form anoverhead that includes water and optionally ammonia, and a liquidbottoms that includes MAS, at least some DAS, and at least about 20 wt %water, cooling and/or evaporating the bottoms, and optionally adding anantisolvent to the bottoms, to attain a temperature and compositionsufficient to cause the bottoms to separate into a DAS-containing liquidportion and a MAS-containing solid portion that is substantially free ofDAS, separating the solid portion from the liquid portion, recoveringthe solid portion, hydrogenating the solid portion in the presence of atleast one hydrogenation catalyst to produce the hydrogenated productcomprising at least one of THF, GBL or BDO, and recovering thehydrogenated product.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a fully integrated process forhydrogenation of fermentation-derived SA to BDO, THF, and GBL anddepicts two-stage deammoniation of DAS with a MAS crystallization stepbetween the two stages.

FIG. 2 schematically illustrates a fully integrated process forhydrogenation of fermentation-derived SA to BDO, THF, and GBL anddepicts two-stage deammoniation of DAS with a MAS crystallization stepbetween the two stages. An optional nanofiltration step is included foradditional purification of SA prior to hydrogenation.

FIG. 3 is a graph showing the solubility of MAS as a function oftemperature in both water and a 30% aqueous DAS solution.

FIG. 4 is a flow diagram showing selected aspects of our process.

FIG. 5 is a graph showing the mole fraction of MAS (Hsu-), DAS (Su-2),and SA (H2Su) as a function of pH at 135° C.

FIG. 6 is a graph similar to that of FIG. 5 at 25° C.

FIG. 7 is a ternary diagram of MAS, DAS and water at selectedtemperatures.

FIG. 8 is a microphotograph of MAS crystals produced by our methods.

FIG. 9 is a microphotograph of SA crystals produced by our methods.

DETAILED DESCRIPTION

It will be appreciated that at least a portion of the followingdescription is intended to refer to representative examples of processesselected for illustration in the drawings and is not intended to defineor limit the disclosure, other than in the appended claims.

Our processes may be appreciated by reference to FIG. 1, which shows inblock diagram form one representative example of our methods.

A growth vessel, typically an in-place steam sterilizable fermentor, maybe used to grow a microbial culture (not shown) that is subsequentlyutilized for the production of the DAS, MAS, and/or SA-containingfermentation broth. Such growth vessels are known in the art and are notfurther discussed.

The microbial culture may comprise microorganisms capable of producingSA from fermentable carbon sources such as carbohydrate sugars.Representative examples of microorganisms include, but are not limitedto, Escherichia coli (E. coli), Aspergillus niger, Corynebacteriumglutamicum (also called Brevibacterium flavum), Enterococcus faecalis,Veillonella parvula, Actinobacillus succinogenes, Mannheimiasucciniciproducens, Anaerobiospirillum succiniciproducens, PaecilomycesVarioti, Saccharomyces cerevisiae, Bacteroides fragilis, Bacteroidesruminicola, Bacteroides amylophilus, Alcaligenes eutrophus,Brevibacterium ammoniagenes, Brevibacterium lactofermentum, Candidabrumptii, Candida catenulate, Candida mycoderma, Candida zeylanoides,Candida paludigena, Candida sonorensis, Candida utilis, Candidazeylanoides, Debaryomyces hansenii, Fusarium oxysporum, Humicolalanuginosa, Kloeckera apiculata, Kluyveromyces lactis, Kluyveromyceswickerhamii, Penicillium simplicissimum, Pichia anomala, Pichia besseyi,Pichia media, Pichia guilliermondii, Pichia inositovora, Pichiastipidis, Saccharomyces bayanus, Schizosaccharomyces pombe, Torulopsiscandida, Yarrowia lipolytica, mixtures thereof and the like.

A preferred microorganism is an E. coli strain deposited at the ATCCunder accession number PTA-5132. More preferred is this strain with itsthree antibiotic resistance genes (cat, amphl, tetA) removed. Removal ofthe antibiotic resistance genes cat (coding for the resistance tochloramphenicol), and amphl (coding for the resistance to kanamycin) canbe performed by the so-called “Lambda-red (λ-red)” procedure asdescribed in Datsenko K A and Wanner B L., Proc. Natl. Acad. Sci. USA2000 Jun. 6; 97(12) 6640-5, the subject matter of which is incorporatedherein by reference. The tetracycline resistant gene tetA can be removedusing the procedure originally described by Bochner et al., J Bacteriol.1980 August; 143(2): 926-933, the subject matter of which isincorporated herein by reference. Glucose is a preferred fermentablecarbon source for this microorganism.

A fermentable carbon source (e.g., carbohydrates and sugars), optionallya source of nitrogen and complex nutrients (e.g., corn steep liquor),additional media components such as vitamins, salts and other materialsthat can improve cellular growth and/or product formation, and water maybe fed to the growth vessel for growth and sustenance of the microbialculture. Typically, the microbial culture is grown under aerobicconditions provided by sparging an oxygen-rich gas (e.g., air or thelike). Typically, an acid (e.g., sulphuric acid or the like) andammonium hydroxide are provided for pH control during the growth of themicrobial culture.

In one example (not shown), the aerobic conditions in the growth vessel(provided by sparging an oxygen-rich gas) are switched to anaerobicconditions by changing the oxygen-rich gas to an oxygen-deficient gas(e.g., CO₂ or the like). The anaerobic environment triggersbioconversion of the fermentable carbon source to SA in situ in thegrowth vessel. Ammonium hydroxide is provided for pH control duringbioconversion of the fermentable carbon source to SA. The SA that isproduced is at least partially neutralized to DAS due to the presence ofthe ammonium hydroxide, leading to the production of a broth comprisingDAS. The CO₂ provides an additional source of carbon for the productionof SA.

In another example, the contents of the growth vessel may be transferredvia a stream to a separate bioconversion vessel for bioconversion of acarbohydrate source to SA. An oxygen-deficient gas (e.g., CO₂ or thelike) is sparged in the bioconversion vessel to provide anaerobicconditions that trigger production of SA. Ammonium hydroxide is providedfor pH control during bioconversion of the carbohydrate source to SA.Due to the presence of the ammonium hydroxide, the SA produced is atleast partially neutralized to DAS, leading to production of a broththat comprises DAS. The CO₂ provides an additional source of carbon forproduction of SA.

In yet another example, the bioconversion may be conducted at relativelylow pH (e.g., 3-6). A base (ammonium hydroxide or ammonia) may beprovided for pH control during bioconversion of the carbohydrate sourceto SA. Depending on the desired pH, due to the presence or lack of theammonium hydroxide, either SA is produced or the SA produced is at leastpartially neutralized to MAS, DAS, or a mixture comprising SA, MASand/or DAS. Thus, the SA produced during bioconversion can besubsequently neutralized, optionally in an additional step, by providingeither ammonia or ammonium hydroxide leading to a broth comprising DAS.As a consequence, a “DAS-containing fermentation broth” generally meansthat the fermentation broth comprises DAS and possibly any number ofother components such as MAS and/or SA, whether added and/or produced bybioconversion or otherwise. Similarly, a “MAS-containing fermentationbroth” generally means that the fermentation broth comprises MAS andpossibly any number of other components such as DAS and/or SA, whetheradded and/or produced by bioconversion or otherwise.

The broth resulting from the bioconversion of the fermentable carbonsource (in either the vessel or the stream, depending on where thebioconversion takes place), typically contains insoluble solids such ascellular biomass and other suspended material, which are transferred viaa stream to a clarification apparatus before distillation. Removal ofinsoluble solids clarifies the broth. This reduces or prevents foulingof subsequent distillation equipment. The insoluble solids can beremoved by any one of several solid-liquid separation techniques, aloneor in combination, including but not limited to, centrifugation andfiltration (including, but not limited to ultra-filtration,micro-filtration or depth filtration). The choice of filtration can bemade using techniques known in the art. Soluble inorganic compounds canbe removed by any number of known methods such as, but not limited to,ion-exchange, physical adsorption and the like.

An example of centrifugation is a continuous disc stack centrifuge. Itmay be useful to add a polishing filtration step followingcentrifugation such as depth filtration, which may include the use of afilter aide such as diatomaceous earth or the like, or more preferablyultra-filtration or micro-filtration. The ultra-filtration ormicro-filtration membrane can be ceramic or polymeric, for example. Oneexample of a polymeric membrane is SelRO MPS-U20P (pH stableultra-filtration membrane) manufactured by Koch Membrane Systems (850Main Street, Wilmington, Mass., USA). This is a commercially availablepolyethersulfone membrane with a 25,000 Dalton molecular weight cut-offwhich typically operates at pressures of 0.35 to 1.38 MPa (maximumpressure of 1.55 MPa) and at temperatures up to 50 C. Alternatively, afiltration step may be employed, such as ultra-filtration ormicro-filtration alone.

The resulting clarified DAS-containing broth or MAS-containing broth,substantially free of the microbial culture and other solids, istransferred via a stream to a distillation apparatus.

The clarified distillation broth should contain DAS and/or MAS in anamount that is at least a majority of, preferably at least about 70 wt%, more preferably 80 wt % and most preferably at least about 90 wt % ofall the diammonium dicarboxylate salts in the broth. The concentrationof DAS as a weight percent (wt %) of the total dicarboxylic acid saltsin the fermentation broth can be easily determined by high pressureliquid chromatography (HPLC) or other known means.

Water and ammonia are removed from the distillation apparatus as anoverhead, and at least a portion is optionally recycled via a stream tothe bioconversion vessel (or the growth vessel operated in the anaerobicmode). Distillation temperature and pressure are not critical as long asthe distillation is carried out in a way that ensures that thedistillation overhead contains water and ammonia, and the distillationbottoms comprises at least some DAS and at least about 20 wt % water. Amore preferred amount of water is at least about 30 wt % and an evenmore preferred amount is at least about 40 wt %. The rate of ammoniaremoval from the distillation step increases with increasing temperatureand also can be increased by injecting steam (not shown) duringdistillation. The rate of ammonia removal during distillation may alsobe increased by conducting distillation under a vacuum or by spargingthe distillation apparatus with a non-reactive gas such as air, nitrogenor the like.

Removal of water during the distillation step can be enhanced by the useof an organic azeotroping agent such as toluene, xylene, hexane,cyclohexane, methyl cyclohexane, methyl isobutyl ketone, heptane or thelike, provided that the bottoms contains at least about 20 wt % water.If the distillation is carried out in the presence of an organic agentcapable of forming an azeotrope consisting of the water and the agent,distillation produces a biphasic bottoms that comprises an aqueous phaseand an organic phase, in which case the aqueous phase can be separatedfrom the organic phase, and the aqueous phase used as the distillationbottoms. Byproducts such as succinamide and succinimide aresubstantially avoided provided the water level in the bottoms ismaintained at a level of at least about 30 wt %.

A preferred temperature for the distillation step is in the range ofabout 50 to about 300° C., depending on the pressure. A more preferredtemperature range is about 90 to about 150° C., depending on thepressure. A distillation temperature of about 110 to about 140° C. ispreferred. “Distillation temperature” refers to the temperature of thebottoms (for batch distillations this may be the temperature at the timewhen the last desired amount of overhead is taken).

Adding a water miscible organic solvent or an ammonia separating solventfacilitates deammoniation over a variety of distillation temperaturesand pressures as discussed above. Such solvents include aprotic,bipolar, oxygen-containing solvents that may be able to form passivehydrogen bonds. Examples include, but are not limited to, diglyme,triglyme, tetraglyme sulfoxides such as dimethylsulfoxide (DMSO), amidessuch as dimethylformamide (DMF) and dimethylacetamide, sulfones such asdimethylsulfone, sulfolane, GBL, polyethyleneglycol (PEG),butoxytriglycol, N-methylpyrolidone (NMP), ethers such as dibutylether,dioxane, diethyleneglycoldimethylether, methyl isobutyl ketone (MIBK),methyl ethyl ketone (MEK) and the like. Such solvents aid in the removalof ammonia from the DAS or MAS in the clarified broth. Regardless of thedistillation technique, it is important that the distillation be carriedout in a way that ensures that at least some DAS and at least about 20wt % water remain in the bottoms and even more advantageously at leastabout 30 wt %.

The distillation can be performed at atmospheric, sub-atmospheric orsuper-atmospheric pressures. The distillation can be a one-stage flash,a multistage distillation (i.e., a multistage column distillation) orthe like. The one-stage flash can be conducted in any type of flasher(e.g., a wiped film evaporator, thin film evaporator, thermosiphonflasher, forced circulation flasher and the like). The multistages ofthe distillation column can be achieved by using trays, packing or thelike. The packing can be random packing (e.g., Raschig rings, Pallrings, Berl saddles and the like) or structured packing (e.g.,Koch-Sulzer packing, Intalox packing, Mellapak and the like). The trayscan be of any design (e.g., sieve trays, valve trays, bubble-cap traysand the like). The distillation can be performed with any number oftheoretical stages.

If the distillation apparatus is a column, the configuration is notparticularly critical, and the column can be designed using well knowncriteria. The column can be operated in either stripping mode,rectifying mode or fractionation mode. Distillation can be conducted ineither batch or continuous mode. In the continuous mode, the broth maybe fed continuously into the distillation apparatus, and the overheadand bottoms continuously removed from the apparatus as they are formed.The distillate from distillation is an ammonia/water solution, and thedistillation bottoms is a liquid, aqueous solution of MAS and DAS, whichmay also contain other fermentation by-product salts (i.e., ammoniumacetate, ammonium formate, ammonium lactate and the like) and colorbodies.

The distillation bottoms can be transferred via a stream to a coolingapparatus and cooled by conventional techniques. Cooling technique isnot critical, although a preferred technique will be described below. Aheat exchanger (with heat recovery) can be used. A flash vaporizationcooler can be used to cool the bottoms down to about 15° C. Cooling to0° C. typically employs a refrigerated coolant such as, for example,glycol solution or, less preferably, brine. A concentration step can beincluded prior to cooling to help increase product yield. Further, bothconcentration and cooling can be combined using methods known such asvacuum evaporation and heat removal using integrated cooling jacketsand/or external heat exchangers.

We found that the presence of some DAS in the liquid bottoms facilitatescooling-induced separation of the bottoms into a liquid portion incontact with a solid portion that at least “consists essentially” of MAS(meaning that the solid portion is at least substantially purecrystalline MAS) by reducing the solubility of MAS in the liquid,aqueous, DAS-containing bottoms. FIG. 3 illustrates the reducedsolubility of MAS in an aqueous 30 wt % DAS solution at varioustemperatures ranging from 0 to 60° C. The upper curve shows that even at0° C. MAS remains significantly soluble in water (i.e., about 20 wt % inaqueous solution). The lower curve shows that at 0° C. MAS isessentially insoluble in a 30 wt % aqueous DAS solution. We discovered,therefore, that MAS can be more completely crystallized out of anaqueous solution if some DAS is also present in that solution. Apreferred concentration of DAS in such a solution is about 30 wt % orhigher. This phenomenon allows crystallization of MAS (i.e., formationof the solid portion of the distillation bottoms) at temperatures higherthan those that would be required in the absence of DAS.

When 50% of the ammonia is removed from DAS contained in an aqueousmedium the succinate species establish an equilibrium molar distributionthat is about 0.1:0.8:0.1 in DAS:MAS:SA within a pH range of 4.8 to 5.4,depending on the operating temperature and pressure. When thiscomposition is concentrated and cooled, MAS exceeds its solubility limitin water and crystallizes. When MAS undergoes a phase change to thesolid phase, the liquid phase equilibrium resets thereby producing moreMAS (DAS donates an ammonium ion to SA). This causes more MAS tocrystallize from solution and continues until appreciable quantities ofSA are exhausted and the pH tends to rise. As the pH rises, the liquidphase distribution favors DAS. However, since DAS is highly soluble inwater, MAS continues to crystallize as its solubility is lower than DAS.In effect, the liquid phase equilibrium and the liquid-solid equilibriaof succinate species act as a “pump” for MAS crystallization, therebyenabling MAS crystallization in high yield.

In addition to cooling, evaporation, or evaporative cooling describedabove, crystallization of MAS can be enabled and/or facilitated byaddition of an antisolvent. In this context, antisolvents may besolvents typically miscible with water but cause crystallization of awater soluble salt such as MAS due to lower solubility of the salt inthe solvent. Solvents with an antisolvent effect on MAS can be alcoholssuch as ethanol and propanol, ketones such as methyl ethyl ketone,ethers such as tetrahydrofuran and the like. The use of antisolvents isknown and can be used in combination with cooling and evaporation orseparately.

The distillation bottoms may be fed via a stream to a separator forseparation of the solid portion from the liquid portion. Separation canbe accomplished via pressure filtration (e.g., using Nutsche orRosenmond type pressure filters), centrifugation and the like. Theresulting solid product can be recovered as a product and dried, ifdesired, by standard methods.

After separation, it may be desirable to treat the solid portion toensure that no liquid portion remains on the surface(s) of the solidportion. One way to minimize the amount of liquid portion that remainson the surface of the solid portion is to wash the separated solidportion with water and dry the resulting washed solid portion. Aconvenient way to wash the solid portion is to use a so-called “basketcentrifuge.” Suitable basket centrifuges are available from The WesternStates Machine Company (Hamilton, Ohio, USA).

The liquid portion of the separator (i.e., the mother liquor) maycontain remaining dissolved MAS, any unconverted DAS, any fermentationbyproducts such as ammonium acetate, lactate, or formate, and otherminor impurities. This liquid portion can be fed via a stream to adownstream apparatus. In one instance, the downstream apparatus may be ameans for making a de-icer by treating in the mixture with anappropriate amount of potassium hydroxide, for example, to convert theammonium salts to potassium salts. Ammonia generated in this reactioncan be recovered for reuse in the bioconversion vessel (or the growthvessel operating in the anaerobic mode). The resulting mixture ofpotassium salts is valuable as a de-icer and anti-icer.

The mother liquor from the solids separation step, can be recycled (orpartially recycled) to the distillation apparatus via a stream tofurther enhance recovery of MAS, as well as further convert DAS to MAS.

The solid portion of the cooling-induced crystallization issubstantially pure MAS and is, therefore, useful for the known utilitiesof MAS.

HPLC can be used to detect the presence of nitrogen-containingimpurities such as succinamide and succinimide. The purity of MAS can bedetermined by elemental carbon and nitrogen analysis. An ammoniaelectrode can be used to determine a crude approximation of MAS purity.

Depending on the circumstances and various operating inputs, there areinstances when the fermentation broth may be a clarified MAS-containingfermentation broth or a clarified SA-containing fermentation broth. Inthose circumstances, it can be advantageous to optionally add MAS; DAS,SA, ammonia and/or ammonium hydroxide to those fermentation broths tofacilitate the production of substantially pure MAS. For example, theoperating pH of the fermentation broth may be oriented such that thebroth is a MAS-containing broth or a SA-containing broth. MAS, DAS, SA,ammonia and/or ammonium hydroxide may be optionally added to thosebroths to attain a broth pH preferably <6 to facilitate production ofthe above-mentioned substantially pure MAS. Also, it is possible thatMAS, DAS and/or SA from other sources may be added as desired. In oneparticular form, it is especially advantageous to recycle MAS, DAS andwater from the liquid bottoms resulting from the distillation step intothe fermentation broth. In referring to the MAS-containing broth, suchbroth generally means that the fermentation broth comprises MAS andpossibly any number of other components such as DAS and/or SA, whetheradded and/or produced by bioconversion or otherwise.

The solid portion can be converted into SA by removing ammonia. This canbe carried out as follows. The solid portion (consisting essentially ofMAS) obtained from any of the above-described conversion processes canbe dissolved in water to produce an aqueous MAS solution. This solutioncan then be distilled at a temperature and pressure sufficient to forman overhead that comprises water and ammonia, and a bottoms thatcomprises a major portion of SA, a minor portion of MAS and water. Thebottoms can be cooled to cause it to separate into a liquid portion incontact with a solid portion that consists essentially of SA and issubstantially free of MAS. The solid portion can be separated from thesecond liquid portion and recovered as substantially pure SA asdetermined by HPLC.

Turning to FIG. 4, we describe one of our particularly preferredprocesses. In FIG. 4, a stream 100 of DAS, which may be a stream ofclarified fermentation broth which contains DAS (among other things), issubjected to reactive evaporation/distillation in distillation column102. The distillation may occur over a range of temperatures such asabout 110 to about 145° C., preferably about 135° C. The pressure in thedistillation column 102 can be over a broad range about 1.5-about 4 bar,preferably about 3.5 bar. Water and ammonia are separated indistillation column 102 and form an overhead 104. The liquid bottoms 106comprises MAS, at least some DAS and at least about 20 wt % water.Typically, bottoms 106 contains about 5-about 20 wt % MAS, about 80 wt%-about 95 wt % water and about 1-about 3 wt % DAS. The pH of thebottoms may be in a range of about 4.6-about 5.6.

The bottoms 106 is streamed to a concentrator 108 which removes watervia overhead stream 110. Concentrator 108 can operate over a range oftemperatures such as about 90° C.-about 110° C., preferably about 100°C. and over a range of pressures such as at about 0.9 bar-about 1.2 bar,preferably about 1.103 bar.

Concentrator 108 produces a bottoms stream 112 which typically containsabout 40 wt %-about 70 wt %, preferably about 55 wt % MAS. Hence, theconcentrator concentrates the amount of MAS typically by about 2-about11 times, preferably about 4 times-about 6 times.

Bottoms stream 112 flows to a first crystallizer 114 which operates at atemperature typically at about 50 to about 70° C., preferably about 60°C. A water overhead stream 116 is produced by the crystallizer. Bottoms118 flows to a centrifuge 120 which produces a solid stream 122 whichtypically has a yield of MAS of about 95%. A remaining liquid flow 124is sent to a second crystallizer 126 which removes additional water byway of overhead stream 128 and operates at a temperature typically atabout 30 to about 50° C., preferably about 40° C. The bottoms stream 130flows to a centrifuge 132. Centrifuge produces a solid stream 134 whichis redissolved with a water stream 136 which introduces water in atemperature range typically of about 70 to about 90° C., preferablyabout 90° C. That stream flows to a first mixer 138 and produces a firstrecycle flow 140 back to the first crystallizer 114.

Remaining liquid from centrifuge 132 flows via stream 141 to thirdcrystallizer 142 which produces an overhead stream 144 of water. Thirdcrystallizer 132 typically operates at a temperature of about 10 toabout 30° C., typically about 20° C. The remaining bottoms flow 146streams to a third centrifuge 148 and solid material produced by thirdcentrifuge 148 flows to a second mixer 150 by way of stream 152. Thatsolid stream is dissolved by a second water stream 154 which introduceswater typically at a temperature range of about 50 to about 70° C.,preferably about 70° C. Second mixer 150 produces a recycle stream 156which is recycled to second crystallizer 126. Remaining material flowsoutwardly of the system from third centrifuge 148 by way of purge stream158 which typically represents about 5 wt % of the total MAS containedin stream 112. It is understood that the desired crystallizationtemperatures in crystallizers 114, 126, and 142 can be attained byevaporation (as depicted), or by indirect contact with an externalcooling medium, or a combination thereof.

FIG. 5 is a graph showing the mole fraction of MAS, DAS and SA as afunction of pH at 135° C., which is typical of the temperature indistillation column 102 of FIG. 4. FIG. 6 is the same as FIG. 5 exceptfor a temperature at 25° C. Those figures show the relative proportionsof the three components depending on the pH at the particulartemperature. In accordance with our methods, the typical operating pH ofthe reactive evaporation/distillation unit 102 and the concentrationunit 108 may be about 5.3 leading to maximum production of MAS. When 50%of the ammonia is removed from DAS contained in an aqueous medium thesuccinate species establish an equilibrium molar distribution that isabout 0.1:0.8:0.1 in DAS:MAS:SA within a pH range of about 4.8 to about5.4, depending on the operating temperature and pressure. Without beingbound by any particular theory, we believe that when this composition isconcentrated and cooled, MAS exceeds its solubility limit in water andcrystallizes. Also, when MAS undergoes a phase change to the solidphase, the liquid phase equilibrium is believed to deliberately reset,thereby producing more MAS (DAS donates an ammonium ion to SA). Webelieve that this causes more MAS to crystallize from solution andcontinues until appreciable quantities of SA are exhausted and the pHtends to rise. As the pH rises, the liquid phase distribution favorsDAS. However, since DAS is highly soluble in water, MAS continues tocrystallize as its solubility is lower than DAS. In effect, the liquidphase equilibrium and the liquid-solid equilibria of succinate speciesact as a “pump” for MAS crystallization, thereby enabling MAScrystallization in high yield.

FIG. 7 is a ternary diagram of MAS, DAS and water at three differenttemperatures, namely 20° C., 35° C. and 60° C. This diagram isillustrative of the solid-liquid equilibrium that causes crystallizationof pure MAS or DAS at different temperatures. We constructed FIG. 7 withexperimental solubility data which shows that if a liquid compositioncontaining MAS, DAS, and water is cooled to cause the separation of asolid portion and if the liquid composition lies to the left of theeutectic points identified as “A,” then liquid-solid equilibriumprinciples suggest that the solid portion will be pure MAS. Conversely,if a liquid composition containing MAS, DAS, and water is cooled tocause the separation of a solid portion and if the liquid compositionlies to the right of the eutectic points identified as “A,” thenliquid-solid equilibrium principles suggest that the solid portion willbe pure DAS. Our processes, depicted representatively in FIG. 4, aredesigned to operate to the left of the eutectic points identified as “A”and, therefore, are expected to produce pure MAS.

Henceforth, representative processes are described with respect to FIGS.4 and 7. Typically, stream 100 is representative of point “P,” which isa DAS containing broth at about 5 wt %. In the reactiveevaporation/distillation step 102, water and ammonia areevaporated/distilled to form a 10 wt % MAS containing solution,typically, which is represented by point “Q.” Subsequently, in theconcentration unit 108, the MAS containing solution is concentrated toform a 60 wt % MAS containing solution, typically, which is representedby point “R.” Finally, the 60 wt % MAS containing solution is cooled (byevaporation, indirect contact cooling, or by a combination thereof) toproduce an approximately 37 wt % MAS containing liquid portionrepresented by point “S” in contact with a solid portion. According toliquid-solid equilibrium principles, our FIG. 7 shows that the solidportion will be essentially pure MAS that is substantially free of DASsince we typically operate our processes to the left of the eutecticpoints.

FIG. 8 is a microphotograph showing representative MAS crystals producedin accordance with our methods. Similarly, FIG. 9 is a microphotographof representative SA crystals produced in accordance with our methods.The micrographs demonstrate that MAS has a crystal shape that isdistinct from that of SA. Henceforth, we have shown that we can produceessentially pure MAS that is both substantially free of DAS and SA usingour methods.

The SA may be dissolved in water to form an aqueous solution of SA whichcan be fed directly to a hydrogenation reactor. The preferredconcentration of SA in the feed solution is about 4% to about 50% andmore preferably about 4% to about 10%.

The SA solution can be further purified using nanofiltration asschematically shown in FIG. 2. Surprisingly, we observed thatnanofiltration is useful in filtering out fermentation-derivedimpurities such as polypeptides and polysaccharides that could impairthe performance of structured hydrogenation catalysts.

Streams comprising SA such as those presented in FIGS. 1 and 2 may becontacted with hydrogen and a hydrogenation catalyst at elevatedtemperatures and pressures to produce a hydrogenation product comprisingTHF, BDO and GBL.

A principal component of the catalyst useful for hydrogenation of SA maybe at least one metal from palladium, ruthenium, rhenium, rhodium,iridium, platinum, nickel, cobalt, copper, iron and compounds thereof.

A chemical promoter may augment the activity of the catalyst. Thepromoter may be incorporated into the catalyst during any step in thechemical processing of the catalyst constituent. The chemical promotergenerally enhances the physical or chemical function of the catalystagent, but can also be added to retard undesirable side reactions.Suitable promoters include but are not limited to metals selected fromtin, zinc, copper, gold, silver, and combinations thereof. The preferredmetal promoter is tin. Other promoters that can be used are elementsselected from Group I and Group II of the Periodic Table, for example.

The catalyst may be supported or unsupported. A supported catalyst isone in which the active catalyst agent is deposited on a supportmaterial by a number of methods such as spraying, soaking or physicalmixing, followed by drying, calcination and, if necessary, activationthrough methods such as reduction or oxidation. Materials frequentlyused as a support may be porous solids with high total surface areas(external and internal) which can provide high concentrations of activesites per unit weight of catalyst. The catalyst support may enhance thefunction of the catalyst agent. A supported metal catalyst is asupported catalyst in which the catalyst agent is a metal.

A catalyst that is not supported on a catalyst support material is anunsupported catalyst. An unsupported catalyst may be platinum black or aRaney® (W.R. Grace & Co., Columbia, Md.) catalyst, for example. Raney®catalysts have a high surface area due to selectively leaching an alloycontaining the active metal(s) and a leachable metal (usually aluminum).Raney® catalysts have high activity due to the higher specific area andallow the use of lower temperatures in hydrogenation reactions. Theactive metals of Raney® catalysts include at least one of nickel,copper, cobalt, iron, rhodium, ruthenium, rhenium, osmium, iridium,platinum, palladium and compounds thereof.

Promoter metals may also be added to the base Raney® metals to affectselectivity and/or activity of the Raney® catalyst. Promoter metals forRaney® catalysts may be selected from transition metals from Groups IIIAthrough VIIIA, IB and IIB of the Periodic Table of the Elements.Examples of promoter metals include but are not limited to chromium,molybdenum, platinum, rhodium, ruthenium, osmium, and palladium,typically at about 2% by weight of the total metal, although otherweight percentages are possible.

The catalyst support can be any solid, inert substance including, butnot limited to, oxides such as silica, alumina and titania; bariumsulfate; calcium carbonate; and carbons. The catalyst support can be inthe form of powder, granules, pellets or the like.

A preferred support material may be at least one of carbon, alumina,silica, silica-alumina, silica-titania, titania, titania-alumina, bariumsulfate, calcium carbonate, strontium carbonate and compounds thereof.Supported metal catalysts can also have supporting materials made fromone or more compounds. More preferred supports are carbon, titania andalumina. Further preferred supports are carbons with a surface areagreater than about 100 m²/g. A further preferred support is carbon witha surface area greater than about 200 m²/g. Preferably, the carbon hasan ash content that is less than about 5% by weight of the catalystsupport. The ash content is the inorganic residue (expressed as apercentage of the original weight of the carbon) which remains afterincineration of the carbon.

A preferred content of the metal catalyst in the supported catalyst maybe from about 0.1% to about 20% of the supported catalyst based on metalcatalyst weight plus the support weight. A more preferred metal catalystcontent range is from about 1% to about 10% of the supported catalyst.

Combinations of metal catalyst and support system may include any one ofthe metals referred to herein with any of the supports referred toherein. Preferred combinations of metal catalyst and support includepalladium on carbon, palladium on alumina, palladium on titania,platinum on carbon, platinum on alumina, platinum on silica, iridium onsilica, iridium on carbon, iridium on alumina, rhodium on carbon,rhodium on silica, rhodium on alumina, nickel on carbon, nickel onalumina, nickel on silica, rhenium on carbon, rhenium on silica, rheniumon alumina, ruthenium on carbon, ruthenium on alumina and ruthenium onsilica.

Further preferred combinations of metal catalyst and support includeruthenium on carbon, ruthenium on alumina, palladium on carbon,palladium on alumina, palladium on titania, platinum on carbon, platinumon alumina, rhodium on carbon, and rhodium on alumina.

A more preferred support is carbon. Further preferred supports arethose, particularly carbon, that have a BET surface area less than about2,000 m²/g. Further preferred supports are those, particularly carbon,that have a surface area of about 300 to 1,000 m²/g.

Typically, hydrogenation reactions may be performed at temperatures fromabout 100° C. to about 300° C. in reactors maintained at pressures fromabout 1000 to about 3000 psig (7×10˜ to about 21×10˜Pa gage).

The method of using the catalyst to hydrogenate a SA or MAS containingfeed can be performed by various known modes of operation. Thus, theoverall hydrogenation process can be performed with a fixed bed reactor,various types of agitated slurry reactors, either gas or mechanicallyagitated, or the like. The hydrogenation process can be operated ineither a batch or continuous mode, wherein an aqueous liquid phasecontaining the precursor to hydrogenate is in contact with a gaseousphase containing hydrogen at elevated pressure and the particulate solidcatalyst.

When the catalyst is used to produce BDO and THF at a desired orcontrolled molar ratio, the hydrogenation is preferably performed at atemperature above about 150° C. and below about 260° C. To obtain a highBDO to THF ratio, the hydrogenation to those desired products shouldadvantageously be performed at or near the lower end of this temperaturerange. The method and conditions can also advantageously influence themolar ratio during hydrogenation. For example, the liquid phase removalof products from the hydrogenation reactor tends to enhance and maximizeBDO production rather than THF. In contrast, continuous vapor removal ofproduct from the hydrogenation reactor tends to maximize THF productionat the expense of BDO. Thus, as a practical consideration, lowtemperature liquid product removal intended to favor BDO productionfavors the use of fixed bed catalytic reactors. On the other hand, vaporphase product removal intended to favor THF production favors the use ofslurry or stirred reactors.

Temperature, solvent, catalyst, reactor configuration, pressure andmixing rate are parameters that can affect the hydrogenation. Therelationships among these parameters may be adjusted to effect thedesired conversion, reaction rate, and selectivity in the reaction ofthe process.

A preferred temperature is from about 25° C. to 350° C., more preferablyfrom about 100° C. to about 350° C., and most preferred from about 150°C. to 300° C. The hydrogen pressure is preferably about 0.1 to about 30MPa, more preferably about 1 to 25 MPa, and most preferably about 1 to20 MPa.

The reaction may be performed neat, in water or in the presence of anorganic solvent. Water is a preferred solvent. Useful organic solventsinclude but are not limited to hydrocarbons, ethers, alcohols and thelike. Alcohols are most preferred, particularly lower alkanols such asmethanol, ethanol, propanol, butanol, and pentanol. The reaction shouldbe carried out with selectivity in the range of at least about 70%.Selectivity of at least about 85% is typical. Selectivity is the weightpercent of the converted material that is THF, BDO and GBL, where theconverted material is the portion of the starting material thatparticipates in the hydrogenation reaction.

The processes may be carried out in batch, sequential batch (i.e. aseries of batch reactors) or in continuous mode in equipment customarilyemployed for continuous processes. The condensate water formed as theproduct of the reaction is removed by separation methods customarilyemployed for such separations.

A preferred hydrogenation reactor may be operated under hydrogenpressure and in the presence of structured catalyst chosen from amongRu, Re, Sn, Pb, Ag, Ni, Co, Zn, Cu, Cr, Mn, or mixtures thereof incatalytic amounts. The hydrogen pressure and the temperature of thereactor may be controlled to obtain the desired hydrogenation product.Typically, the reactor feed for hydrogenation is maintained from about100 C to about 210 C, but more preferably about 135 C to about 150 C.

Suitable catalysts for use in the hydrogenation of MAS can be preparedby one skilled in the art or may include but are not limited tocatalysts commercially sold by JOHNSON MATTHEY®, such as 5% Ru/C(D103002-5, Lot C-6553, 55.9% H₂O; 13101023-5, Lot C-7154, 51.5% H₂O;and D101023-5, Lot C-6170, 58.0% H₂O), 5% Pd/C (A503038-5, Lot C-8882,60.9% H₂O), 4% Pd, 1% Pt, 3% Bi/C (430, Lot C-7155, 57.0% H₂O), or 5%Rh/C (Lot C-5322, 61.6% H₂O) and the like.

Examples of suitable catalyst supports include those listed in Table 1.

TABLE 1 Sources of Catalysts for hydrogenation of MAS Surface area Volcap* # Precursor Vendor Sample # m²/g mL H2O/g* pH Powdered supportmaterials 1 Carbon support 22 JM 2 Norit SX 1G Norit Americas 3 Norit SX1 Norit Americas Particulate/Extruded support materials 4 Norit ROY 0.8Norit Americas 570245 1225 1.6 neutral 5 Norit RO 0.8 Norit Americas670529 1300 1.6 basic 6 Norit R1 Norit Americas 670722 1450 1.4 7 NoritROX 0.8 Norit Americas 590028 1225 1.5 neutral 8 PICATAL TA80 Veolia PUI4850 1350-1450 1.5 basic 9 PICATAL TA100 Veolia PUI 4851 1500-1650 1.5basic 10 TiO2 Saint-Gobain 20006120314    4.2 0.4 11 Silica Zoefree 80D4.0** *volume water needed to completely fill the pores of the supportmaterial **EtOH:H₂O (1:1) was used to determine the Vol cap parameterand to make the mixed metal solution for impregnation.

BDO, THF, and GBL can be separated by known distillation methods.Further, GBL can be partially or fully recycled to the hydrogenationstep to maximize the yield of BDO, THF, or both.

EXAMPLES

The processes are illustrated by the following non-limitingrepresentative examples. In a number of the examples, a synthetic,aqueous DAS solution was used in place of an actual clarifiedDAS-containing fermentation broth. Other examples use an actualclarified DAS-containing fermentation broth.

The use of a synthetic DAS solution is believed to be a good model forthe behavior of an actual broth in our processes because of thesolubility of the typical fermentation by-products found in actualbroth. The major by-products produced during fermentation are ammoniumacetate, ammonium lactate and ammonium formate. If these impurities arepresent during the distillation step, one would not expect them to loseammonia and form free acids in significant quantities until all of theDAS had been converted to MAS. This is because acetic acid, lactic acidand formic acid are stronger acids than the second acid group of SA(pKa=5.48). In other words, acetate, lactate, formate and evenmonohydrogen succinate are weaker bases than the dianion succinate.Furthermore, ammonium acetate, ammonium lactate and ammonium formate aresignificantly more soluble in water than MAS, and each is typicallypresent in the broth at less than 10% of the DAS concentration. Inaddition, even if the acids (acetic, formic and lactic acids) wereformed during the distillation step, they are miscible with water andwill not crystallize from water. This means that the MAS reachessaturation and crystallizes from solution (i.e., forming the solidportion), leaving the acid impurities dissolved in the mother liquor(i.e., the liquid portion).

Example 1

This example demonstrates conversion of a portion of DAS into MAS viadistillation and recovery of MAS solids from distillation bottoms liquidvia cooling-induced crystallization.

A three neck 500 mL round bottom flask was fitted with a thermometer andDean Stark trap topped with a reflux condenser. The vent from the refluxcondenser went to a scrubbing bottle which contained 100 g of a 1.4Macetic acid solution. The flask was charged with 400 g of a 10% DASaqueous solution (pH 8.5). The contents of the flask were stirred with amagnetic stirrer and heated with a heating mantle to distill off 320.6 gof distillate (an aqueous ammonia solution) which was removed via theDean Stark trap. Analysis of the distillate indicated that about 20% ofthe contained ammonia had been removed from the charged DAS duringdistillation (i.e., the salts in the bottoms liquid were about 40% MASand about 60% DAS). Only traces of ammonia were found in the scrubbingbottle. The final temperature of the pot as the last drop distilled overwas 110° C. The residue (bottoms liquid) in the pot (73.4 g which wasabout 53% water) was placed in a flask and allowed to cool to roomtemperature overnight. Upon cooling to room temperature, white needlesof MAS were formed. The white solids were separated via vacuumfiltration, yielding 14 g of wet crystals (solid portion) and 56 g ofmother liquor (liquid portion). A portion of the wet crystals (7 g) wasdried overnight in a vacuum oven, yielding 6 g of dried solids whichcontained 0.4% water as determined by Karl-Fisher analysis. Analysis ofthe solids portion with HPLC revealed that the solids portion was freeof non-MAS nitrogen-containing impurities (e.g., succinimide andsuccinamide).

Example 2

This example demonstrates mother liquor recycle.

A 1-L round bottom flask was charged with 800 g of a synthetic 4.5% DASsolution, and then a distillation head was attached to the flask. Thecontents of the flask were distilled at atmospheric pressure leaving 67g of residue (bottoms liquid) in the flask. The bottoms liquid containedapproximately 45% water. Ammonia analyses of the distillates indicatethat the first distillation cycle removed about 29% of the ammonia,making a 42/58 mol/mol mixture of DAS and MAS. The residue (bottomsliquid) was then removed from the flask and placed in a beaker equippedwith a water bath. The beaker contents were cooled to 20° C. withstirring. Once the residue reached 20° C., it was seeded with a fewcrystals of MAS and allowed to stir for 30 minutes. The temperature ofthe bath was then lowered to 15° C. and held for 30 minutes. Thetemperature was then lowered to 10° C. and held for 30 minutes. Thetemperature was then cooled to 5° C. and held for 30 minutes and finallyto 0° C. where it was held for 30 minutes. The slurry (consisting ofsolid and liquid portions) was then quickly filtered using a pre-cooledsintered glass filter funnel and vacuum flask. The solids were dried ina vacuum oven yielding 13.9 g of dry MAS solids. The mother liquor(liquid portion, 47.2 g) was then combined with 800 g of synthetic 4.5%DAS solution and distilled, leaving 86.6 g of residue (bottoms liquid).In the second distillation (i.e., mother liquor recycle run) about 28%of the ammonia from the total amount of DAS present was removed. Theresidue (bottoms liquid) was then cooled (crystallized) in a similarmanner. However, the solution became cloudy at 46° C., so it was seededat 46° C. and allowed to slowly cool to room temperature overnight whilestirring. The next day the temperature was slowly ramped down by 5° C.increments to 0° C. The slurry (solid and liquid portions) was filteredas before, and the solids dried, yielding 23.5 g of MAS solids. This isequal to about a 75% recovery of the SA equivalents in the 800 g offresh DAS solution distilled. The recovered solids from the first cyclewere 95% MAS (about 5% water). In the second cycle, the solids were 97%MAS (about 3% water). The mother liquor from the second cycle contained28.8% SA equivalents (i.e., as SA salts).

Example 3

This example demonstrates the absence of amide and imide species in thesolid portion of cooled distillation bottoms.

A 1-L round bottom flask was charged with 800 g of a synthetic 4.5% DASsolution. The flask was fitted with a five tray 1″ Oldershaw sectionwhich was capped with a distillation head. The distillate was collectedin an ice cooled receiver. The contents of the flask were heated with aheating mantel and stirred with a magnetic stirrer. The contents of theflask were distilled giving 721.1 g of an overhead distillate and 72.2 gof a liquid residue in the flask (i.e. distillation bottoms). Theaqueous ammonia distillate was titrated revealing a 0.34% ammoniacontent (i.e., about 55% conversion of DAS to MAS). The hot distillationbottoms (approximately 47% salt solution of DAS and MAS) were thenplaced in a 125 mL Erlenmeyer flask and allowed to cool slowly to roomtemperature while stirring over night. The next morning the cloudysolution was cooled to 15° C. and held for 60 minutes, then cooled to10° C. and held for 60 minutes and finally cooled to 5° C. and held for60 minutes while stirring. The resulting white slurry was filteredyielding 12.9 g of wet crystals and 55.3 g of mother liquor. Thecrystals were dissolved in 25.8 g of distilled water. HPLC analysis ofthe crystal solution revealed no detectable amounts of amide or imidespecies. However, HPLC analysis of the mother liquor revealed a trace ofsuccinamic acid, but no detectable succinamide or succinimide.

Example 4

This example produces a solid portion of a cooled distillation bottomsthat consists essentially of MAS and is substantially free of DAS.

A three neck 1-L round bottom flask was fitted with an addition funneland a 1″ five tray Oldershaw column which was capped with a distillationhead. An ice cooled receiver was used to collect the distillate. Theflask was charged with 800 g of a synthetic 4.5% DAS solution. Thecontents of the flask were heated with a heating mantel and stirred witha magnetic stirrer. Distillation was started. While the distillationoccurred an additional 1600 g of the 4.5% DAS solution was slowly addedto the flask at the same rate as distillate was taken. A total of 2135 gof distillate was taken overhead. Titration of the distillate revealedthe overhead was a 0.33% ammonia solution. The hot aqueous distillationbottoms (253.8 g) was removed from the flask and placed in an Erlenmeyerflask. The distillation bottoms were allowed to slowly cool to roomtemperature while stirring overnight. The contents of the flask wereseeded and allowed to stir for 30 minutes. The slurry was then cooled to15° C. and held for 60 minutes, then 10° C. and held for 60 minutes andfinally to 5° C. and held for 60 minutes all while stirring. The slurrywas filtered cold and the solids (i.e., the solid portion) washed threetimes with about 20 g portions of a cold (about 5 C) 20% sodium chloridesolution to displace the mother liquor (i.e., the liquid portion). Airwas sucked through the cake for several minutes to remove as much liquidas possible. The solids were then dried in a vacuum oven at 75° C. forone hour yielding 7.2 g of white crystals. Carbon and nitrogen analysesof the solids revealed a 4.06 atomic ratio of carbon to nitrogen (i.e.,a 1.01 ratio of ammonia to SA or about 99% MAS). That a ratio of 1.00was not obtained is believed to be attributable to incomplete washing ofthe solids.

Example 5

This example demonstrates the effect of solvents on ammonia evolutionfrom aqueous DAS. Run 5 is the control experiment where no solvent ispresent.

The outer necks of a three neck 1-L round bottom flask were fitted witha thermometer and a stopper. The center neck was fitted with a five tray1″ Oldershaw section. The Oldershaw section was topped with adistillation head. An ice cooled 500 mL round bottom flask was used asthe receiver for the distillation head. The 1-L round bottom flask wascharged with distilled water, the solvent being tested, SA andconcentrated ammonium hydroxide solution. The contents were stirred witha magnetic stirrer to dissolve all the solids. After the solidsdissolved, the contents were heated with the heating mantle to distill350 g of distillate. The distillate was collected in the ice cooled 500mL round bottom flask. The pot temperature was recorded as the last dropof distillate was collected. The pot contents were allowed to cool toroom temperature and the weight of the residue and weight of thedistillate were recorded. The ammonia content of the distillate was thendetermined via titration. The results were recorded in Table 2.

TABLE 2 Run # 1 2 3 4 5 Name of Acid charged Succinic Succinic SuccinicSuccinic Succinic Wt Acid Charged (g) 11.81 11.79 11.8 11.79 11.8 MolesAcid Charged 0.1 0.1 0.1 0.1 0.1 Wt 28% NH3 Solution Charged (g) 12.1112.09 12.1 12.11 12.1 Moles NH3 Charged 0.2 0.2 0.2 0.2 0.2 Name ofSolvent Diglyme PG* GBL** butoxy triglycol none Wt Solvent Charged (g)400 400.1 400 400 0 Wt Water Charged (g) 400 400 400 400 800 WtDistillate (g) 350.5 351.6 350.1 350.7 351 Wt Residue (g) 466.3 461.7464.3 460.9 466 % Mass Accountability 99.1 98.7 98.9 98.5 99.2 Wt % NH3in distillate (titration) 0.48 0.4 0.27 0.47 0.13 Moles NH3 indistillate 0.099 0.083 0.056 0.097 0.027 % NH3 removed in Distillate49.5 42 28 49 13.4 % First NH3 removed in Distillate 99 84 56 98 27 %Second NH3 removed in Distillate 0 0 0 0 0 Final Pot Temp (° C.) 101 120110 107 100 *PG is propylene glycol **GBL is gamma butyrolactone

Example 6

This example produced a solid portion from a cooled distillation bottomsthat consists essentially of SA and is substantially free of MAS.

A 300 mL Parr autoclave was charged with 80 g of synthetic MAS and 120 gof water. The autoclave was sealed and the contents stirred and heatedto ˜200° C. at an autogenic pressure of ˜190 psig. Once the contentsreached temperature, water was fed to the autoclave at a rate of ˜2g/min and vapor removed from the autoclave at a rate of ˜2 g/min with aback pressure regulator. Vapor exiting the autoclave was condensed andcollected in a receiver. The autoclave was run under these conditionsuntil a total of 1020 g of water had been fed and a total of 1019 g ofdistillate collected. The distillate was titrated for ammonia content(0.29% ammonia by weight). This translates into a ˜29% conversion of MASto SA. The contents of the autoclave (194.6 g) were partially cooled anddischarged from the reactor. The slurry was allowed to stand understirring at room temperature over night in an Erlenmeyer flask. Theslurry was then filtered and the solids rinsed with 25 g of water. Themoist solids were dried in a vacuum oven at 75° C. for 1 hr yielding 9.5g of SA product. Analysis via an ammonium ion electrode revealed 0.013mmole ammonium ion/g of solid. HPLC analysis revealed the solids were SAwith 0.8% succinamic acid impurity.

Example 7

This example used DAS-containing clarified fermentation broth derivedfrom a fermentation broth containing E. Coli strain ATCC PTA-5132. Thisexample produced a solid portion of a cooled distillation bottoms thatconsists essentially of MAS and is substantially free of DAS.

A three neck 1-L round bottom flask was fitted with an addition funneland a 1″ five tray Oldershaw column which was capped with a distillationhead. An ice cooled receiver was used to collect the distillate. Theflask was charged with 800 g of clarified DAS-containing fermentationbroth which contained 4.4% DAS, 1% ammonium acetate, 0.05% ammoniumformate and 0.03% ammonium lactate. The contents of the flask wereheated with a heating mantel and stirred with a magnetic stirrer.Distillation was started. While the distillation ran, an additional 2200g of the broth solution was slowly added to the flask at the same rateas distillate was removed. A total of 2703 g of distillate was taken asoverhead. Titration of the distillate revealed the overhead was a 0.28%ammonia solution. The hot aqueous distillation bottoms solution (269.7g) was removed from the flask and placed in an Erlenmeyer flask. Thedistillation bottoms were allowed to slowly cool to room temperaturewhile stirring overnight. The next day, the contents of the flask wereseeded and allowed to stir for 30 minutes. The slurry was then cooled to15° C. and held for 30 minutes, then to 10° C. and held for 30 minutesand finally to 5° C. and held for 30 minutes, all while stirring. Theslurry was filtered cold and air was sucked through the cake for severalminutes to remove as much liquid as possible. Light brown solids (72.5g) and dark brown mother liquor (188.4 g with a pH of 6.4) wereobtained. The solids were recrystallized to remove the mother liquor bydissolution in 72 g of water at 50° C. The solution was then allowed toslowly cool to room temperature while stirring overnight. The next daythe contents of the flask were seeded and stirred for 30 minutes. Theslurry was then cooled to 15° C. and held for 30 minutes, then to 10° C.and held for 30 minutes, and finally to 5° C. and held for 30 minutes,all while stirring. The slurry was filtered cold and air was suckedthrough the cake for several minutes to remove as much liquid aspossible, yielding 110 g of brown mother liquor (pH 5.0). The solidswere then dried in a vacuum oven at 75° C. for one hour yielding 24 g ofoff-white crystals. Carbon and nitrogen analyses of the solids revealeda 4.04 molar ratio of carbon to nitrogen (i.e. a 1.01 ratio of ammoniato SA or ˜99% MAS). HPLC analysis revealed that the MAS contained 0.07%succinamic acid but no detectable succinamide, succinimide or acetatespecies. In other words, the MAS was free of DAS and otherwisesubstantially pure.

Example 8

This example used fermentation derived MAS from a fermentation brothcontaining E. Coli strain ATCC PTA-5132. This example produced a solidportion from a cooled distillation bottoms that consists essentially ofSA and is substantially free of MAS.

A 300 mL Parr autoclave was charged with 80 g of broth derived MAS and120 g of water. The autoclave was sealed and the contents stirred andheated to ˜202° C. at an autogenic pressure of ˜205 psig. Once thecontents reached temperature, water was fed to the autoclave at a rateof ˜2 g/min and vapor was removed from the autoclave at a rate of ˜2g/min with a back pressure regulator. Vapor exiting the autoclave wascondensed and collected in a receiver. The autoclave was run under theseconditions until a total of 905 g of water had been fed and a total of908 g of distillate collected. The distillate was titrated for ammoniacontent (0.38% ammonia by weight). This translates into a ˜34%conversion of MAS to SA. The contents of the autoclave (178.2 g) werepartially cooled and discharged from the reactor. The slurry was allowedto stand under stirring at room temperature over night in an Erlenmeyerflask. The slurry was then filtered and the solids rinsed with 25 g ofwater. The moist solids were dried in a vacuum oven at 75° C. for 1 hryielding 8.5 g of SA product. Analysis via an ammonium ion electroderevealed 0.027 mmole ammonium ion/g of solid. HPLC analysis revealed thesolids were SA with 1.4% succinamic acid and 0.1% succinamideimpurities.

Example 9

This example used an ammonia releasing solvent to aid deammoniation.This example produced a solid portion from a cooled distillation bottomsthat consists essentially of SA and is substantially free of MAS.

A 500 mL round bottom flask was charged with 29 g of MAS solids, 51 g ofwater and 80 g of triglyme. The flask was fitted with a 5 tray 1″ glassOldershaw column section which was topped with a distillation head. Anaddition funnel containing 2500 g of water was also connected to theflask. The flask was stirred with a magnetic stirrer and heated with aheating mantel. The distillate was collected in an ice cooled receiver.When the distillate started coming over the water in the addition funnelwas added to the flask at the same rate as the distillate was beingtaken. A total of 2491 g of distillate was taken. The distillatecontained 2.3 g of ammonia, as determined by titration. This means ˜63%of the MAS was converted to SA. The residue in the flask was then placedin an Erlenmeyer flask and cooled to −5° C. while stirring. Afterstirring for 30 minutes the slurry was filtered while cold yielding 15.3g of solids. The solids were dissolved in 15.3 g of hot water and thencooled in an ice bath while stirring. The cold slurry was filtered andthe solids dried in a vacuum oven at 100° C. for 2 hrs yielding 6.5 g ofsuccinic acid. HPLC analysis indicated that the solids were SA with0.18% succinamic acid present.

Example 10

This example used an ammonia releasing solvent to aid deammoniation.This example produced a solid portion of a cooled distillation bottomsthat consists essentially of MAS and is substantially free of DAS.

A 500 mL round bottom flask was charged with 80 g of an aqueous 36% DASsolution and 80 g of triglyme. The flask was fitted with a 5 tray 1″glass Oldershaw column section which was topped with a distillationhead. An addition funnel containing 700 g of water was also connected tothe flask. The flask was stirred with a magnetic stirrer and heated witha heating mantel. The distillate was collected in an ice cooledreceiver. When the distillate started coming over the water in theaddition funnel was added to the flask at the same rate as thedistillate was being taken. A total of 747 g of distillate was taken.The distillate contained 3.7 g of ammonia, as determined by titration.This means ˜57% of the ammonia was removed. In other words, all of theDAS was converted into MAS and ˜44% of the MAS was further convertedinto SA. The residue in the flask was then placed in an Erlenmeyer flaskand cooled to 5° C. while stirring. After stirring for 30 minutes theslurry was filtered while cold and the solids dried in a vacuum oven at100° C. for 2 hrs yielding 10.3 g of MAS. Analysis indicated that thesolids were MAS with 0.77% succinamic acid and 0.14% succinimidepresent.

Example 11

This example demonstrates the use of an azeotroping solvent,particularly separation of MAS from other by-products in the broth.

A three neck 500 mL round bottom flask was fitted with a thermometer, a250 mL addition funnel and a Dean Stark trap topped with a refluxcondenser. The flask was charged with 100 g of toluene and 100 g of a˜9% DAS broth solution (which also contained about 1% ammonium acetateand ammonium formate combined). The addition funnel was charged with 250g of the 9% diammonim succinate broth solution. The contents of theflask were stirred with a magnetic stirrer and heated with a heatingmantel bringing the contents to boil. The contents of the additionfunnel were added slowly to the flask allowing the toluene-waterazeotope to distill into the Dean-Stark trap with return of the tolueneto the flask. After all the contents of the addition funnel had beenadded (at a rate substantially equal to the distillate) the contentswere allowed to further reflux until a total of 277.5 g of aqueous phasehad been collected from the Dean Stark trap. The contents of the flaskwere removed while hot and the two phases separated in a warm separatoryfunnel. The aqueous phase was cooled in an ice bath while being stirred.The resulting solids were recovered via filtration using a sinteredglass funnel. The mother liquor was dark brown and the filtered solidswere off-white. The solids were dried in a vacuum oven and analyzed viaHPLC. The dried solids (5.7 g) were ˜96% monoammonium succinate and ˜1%ammonium acetate with the rest being water.

Example 12

A pressure distillation column was constructed using an 8 ft long 1.5″316 SS Schedule 40 pipe packed with 316 SS Propak packing. The base ofthe column was equipped with an immersion heater to serve as thereboiler. Nitrogen was injected into the reboiler via a needle valve topressure. The overhead of the column had a total take-off line whichwent to a 316 SS shell and tube condenser with a receiver. The receiverwas equipped with a pressure gauge and a back pressure regulator.Material was removed from the overhead receiver via blowcasing through aneedle valve. Preheated feed was injected into the column at the top ofthe packing via a pump. Preheated water was also injected into thereboiler via a pump. This column was operated at 30 psig pressure whichgave a column temperature of 137° C. The top of the column was fed asynthetic 10% DAS solution at a rate of 5 mL/min and water was fed tothe reboiler at a rate of 5 mL/min. The overhead distillate rate was 8mL/min and the residue rate was 2 mL/min. Titration of the distillatefor ammonia indicated that the ˜47% of the ammonia had been removed inthe distillate (i.e. the conversion to MAS was ˜94%). The residue liquidwas ˜20% MAS and HPLC analysis of the residue indicated an ˜3%inefficiency to succinamic acid.

Example 13

A portion of the residue (800 g) from Example 12 was concentrated via abatch distillation to ˜59% MAS solution (i.e. 530 g of water wasdistilled off). The residue was then cooled to 5° C. while stirring. Theresulting slurry was filtered and the solids dried in a vacuum oven at75° C. for 1 hour yielding 52.5 g of MAS solids (i.e. ˜32% recovery).HPLC analysis indicated that the solids contained 0.49% succinamic acidand no succinimide.

Example 14

A second portion of the pressure column residue (3200 g) from Example 12was placed in the evaporative crystallizer and concentrated to ˜72% MASby distilling off 2312 g of water at 60° C. under vacuum. The resultinghot slurry was centrifuged and the recovered solids dried in the vacuumoven at 75° C. for one hour yielding 130.7 g of MAS solids. The motherliquor from the centrifuging step was allowed to cool to roomtemperature forming a second crop of crystals. This slurry was filteredand the recovered solids were dried at 75° C. under vacuum yielding114.8 g of MAS solids. Based on the succinate concentration of the feedto the crystallizer, a 20% and 18% recovery was realized for the firstand second crops, respectively (i.e. a 38% overall recovery). HPLCanalysis of the two crops of solids indicated that the first crop had nodetectable succinamic acid and succinimide while the second crop had0.96% succinamic acid and 0.28% succinimide.

Comparative Example 1

This example demonstrates that an atmospheric distillation of an aqueousMAS solution removes very little ammonia when triglyme is not present.

A 500 mL round bottom flask was charged with 30 g of MAS solids and 120g of water. The flask was fitted with a 5 tray 1″ glass Oldershaw columnsection which was topped with a distillation head. An addition funnelcontaining 600 g of water was also connected to the flask. The flask wasstirred with a magnetic stirrer and heated with a heating mantel. Thedistillate was collected in an ice cooled receiver. When the distillatestarted coming over the water in the addition funnel was added to theflask at the same rate as the distillate was being taken. A total of 606g of distillate was taken. The distillate contained 0.15 g of ammonia,as determined by titration. This means ˜4% of the MAS was converted toSA.

Comparative Example 2

This example demonstrates the decrease in ammonia removal for DAS whentriglyme is not present.

A 500 mL round bottom flask was charged with 80 g of an aqueous 36% DASsolution and 80 g of water. The flask was fitted with a 5 tray 1″ glassOldershaw column section which was topped with a distillation head. Anaddition funnel containing 1200 g of water was also connected to theflask. The flask was stirred with a magnetic stirrer and heated with aheating mantel. The distillate was collected in an ice cooled receiver.When the distillate started coming over the water in the addition funnelwas added to the flask at the same rate as the distillate was beingtaken. A total of 1290 g of distillate was taken. The distillatecontained 2.2 g of ammonia, as determined by titration. This means ˜44%of the DAS was converted to MAS.

Examples 15-22

A series of batch hydrogenation reactions are performed to evaluate theeffectiveness of the catalysts in the hydrogenation offermentation-derived SA. The reactions are conducted in a stirrable 125ml autoclave rated up to 2,500 psig.

Hydrogenation experiments conducted by reducing the catalysts in situfor determination of catalyst compositions suitable for hydrogenation offermentation-derived SA. The experiments are conducted in the 125 mlautoclave as follows: (1) 0.5100 grams of a 1% ruthenium solutionderived from RuCl₃.×H₂O, 0.2780 g of a HReO₄ solution (7.7% Re fromRe₂O₇), 0.5035 g of particulate acidic carbon (BET 1,500 m²/g), anappropriate amount of 12.5% Sn solution prepared from SnCl₄;5H2O, and 35g of 7% aqueous SA solution are mixed in the autoclave; (2) Hydrogen ischarged to the reactor to 1,200 psig; (3) The reactor contents areheated to 250° C. at 700 rpm and maintained at 250° C. for 3 hours; (4)The reactor is cooled and vented; and (5) A sample of the slurry in thereactor is filtered and analyzed for BDO, THF, GBL, 1-propanol, andn-butanol using gas chromatography.

Hydrogenation experiments are also conducted by pre-reducing thecatalysts deposited on a support to determine catalysts compositions andsupports suitable for hydrogenation of fermentation-derived SA. Thecatalyst is prepared as follows: (1) 2.0305 grams of 1% rutheniumsolution derived from RuCl₃.×H₂O, 1.104 grams of 7.7% rhenium solutionderived from HReO₄, appropriate amount of 12.5% Sn solution preparedfrom SnCl₄;5H2O, and 2.03 grams of particulate carbon support (averageparticle size about 20 micron) characterizes as intrinsically acidic(pH=4-4.5) with BET surface area of about 1,500 m²/g are slurried; (2)The slurry is dried at about 100 to about 120° C., under vacuum andnitrogen purge; (3) The catalysts is reduced under hydrogen-helium flowfor about 8 hours at about 300° C.; (4) The catalysts is cooled underhelium to about 50° C. and passivated for 30 minutes under 1% O₂ in N₂.The hydrogenation experiments are conducted in the 125 ml autoclave asfollows: (1) About 0.1 to 0.5 g of the catalyst and 35 g of 7% aqueousSA solution are mixed in the autoclave; (2) Hydrogen is charged to thereactor to 1,200 psig; (3) The reactor contents are heated to 250° C. at700 rpm and maintained at 250° C. for 3 hours; (4) The reactor is cooledand vented; and (5) A sample of the slurry in the reactor is filteredand analyzed for BDO, THF, GBL, 1-propanol, and n-butanol using gaschromatography.

Hydrogenation of SA crystallized from simulated broth composed ofreagent grade chemicals and de-ionized water is conducted to determinethe effectiveness of the catalysts for SA hydrogenation. SA forhydrogenation is prepared as follows: (1) an aqueous solution consistingof 25% (wt.) SA, 2.5% (wt.) acetic acid, 0.25% (wt.) formic acid, and0.25% (wt.) lactic acid is prepared at 80° C. in a jacketed kettleequipped with a reflux condenser; (2) The hot solution is cooled to 20°C. by cooling the solution over a 3 hour period following a linearcooling profile; (3) The solution is seeded with 0.1 g of SA crystals at75° C.; (4) The slurry is allowed to equilibrate at 20° C. for 1 hour;(5) The slurry is filtered with vacuum filtration and washed with 20 gof water; (6) 50 g of the cake (10% wt. moisture) is dissolved in 593 gof deionized water (7% wt. solution).

Hydrogenation of SA crystallized from fermentation-derived broth isconducted to establish the effect of carryover impurities fromfermentation. Fermentation-derived SA for hydrogenation is prepared asfollows: (1) A fermentation-derived broth containing 4.5% (wt.) DAS,0.45% (wt.) ammonium acetate, 0.05% (wt.) ammonium formate, and 0.05%(wt.) ammonium lactate is deammoniated and concentrated resulting in agreater than 25% SA solution; (2) The hot solution is cooled to 20° C.by cooling the solution over a 3 hour period following a linear coolingprofile; (3) The solution is seeded with 0.1 g of SA crystals at 75° C.;(4) The slurry is allowed to equilibrate at 20° C. for 1 hour; (5) Theslurry is filtered with vacuum filtration and washed with 20 g of water;(6) 50 g of the cake (10% wt. moisture) is dissolved in 593 g ofdeionized water (7% wt. solution).

Representative results are presented in Examples 15-22 in Table 5.

TABLE 5 Representative hydrogenation results Ex. Catalysts SA BDO THFGBL PrOH BuOH 15 1%Ru:4%Re^((a)) S 0.08 16.9 0.08 1.45 1.21 161%Ru:4%Re^((a)) F 0.08 16.9 0.08 1.45 1.21 17 1%Ru:0.8%Re:0.4%^((a)) S18 1%Ru:0.8%Re:0.4%^((a)) F 19 1%Ru:4%Re^((b)) S 0.88 14.8 0.29 2.161.59 20 1%Ru:4%Re^((b)) F 0.88 14.8 0.29 2.16 1.59 211%Ru:0.8%Re:0.4%^((b)) S 22 1%Ru:0.8%Re:0.4%^((b)) F S = SA derived fromsimulated broth derived from reagent chemicals, F = SA derived fromfermentation broth, ^((a))= catalyst reduced in situ, ^((b))=Pre-reduced catalytst, PrOH = propanol, and BuOH = butanol.

Example 23 Preparation of Exemplary Catalyst 1 (Ru, Sn (Al Sol)

74.8 g of Al i-propoxide and 86.7 g of 2-methylpentane-2,4-diol weremixed at room temperature and heated at 383 K for 3 hours understirring. The alcohols released from the exchange reaction were removedby rot evaporation at 330° K under vacuum. 26.65 g of the Ru(NO)(NO₃)₃solution was also rot evaporated to remove excess HNO₃ and the soliddissolved in 60 g ethanol. 13.25 g of Tin (O t-Bu)₄ was dissolved in 80g of 1-butanol. The two solutions were added to the aluminum-diolmixture and stirred for 2 hours. After removing the alcohols, 123 g ofwater was added to the mixture. The gel formed was aged for two days anddried initially in a rota-evaporator at 373° K under vacuum andadditionally in a vacuum oven at 383° K for 24 hours. The catalyst wasactivated by loading in a glass tube, purged with He at 20 cc/min for 30min. Heating started at 1° C./min to 673° K. When the temperaturereached 473° K, the flow was switched to 20 cc/min hydrogen and kept atthat setting for 4 hours. The temperature was next reduced to ambientand the flow switched back to He. The catalyst prepared was kept underAr in suba-sealed glass vials.

Example 24 Preparation of Exemplary Catalyst 2 [(Ru (Al Sol), Sn(Impregnation)]

Ru—Al₂O₃ was prepared similarly to Exemplary Catalyst 1 in Example 23except that the Sn solution was not added initially. The Sn solution wasadded to the Ru—Al₂O₃ powder obtained after drying in a vacuum oven at383° K for 24 hours. The solvent butanol was rot evaporated and thesolid dried again in a vacuum oven at 383° K for 24 hours. The catalystreduction was done as with Exemplary Catalyst 1 in Example 23.

Example 25 Preparation of Exemplary Catalyst 3 [(Sn (Al Sol), Ru(Impregnation)]

Sn—Al₂O₃ was prepared similarly to Exemplary Catalyst 1 in Example 23except that the Ru solution was not added initially. The Ru solution wasadded to the Sn—Al₂O₃ powder obtained after drying in a vacuum oven at383° K for 24 hours. The solvent ethanol was rot evaporated and thesolid dried again in vacuum oven at 383° K for 24 h. The catalystreduction was done as in Example 23.

Example 26 Preparation of Exemplary Catalyst 4 [(Al Sol), Ru, Sn(Impregnation)]

Sol-gel Al₂O₃ was prepared similarly to Exemplary Catalyst 1 in Example23, except that the Ru and Sn solution were not added initially. The Rusolution was added to the Al₂O₃ powder obtained after drying in a vacuumoven at 383° K for 24 hours. The solvent ethanol was rot evaporated andthe solid dried again in a vacuum oven at 383° K for 24 hours. The tinsolution was subsequently impregnated on the Ru—Al₂O₃ using the sameprotocol as in Example 24. The catalyst reduction was done as in Example23.

Example 27 Exemplary Catalyst 5, Synthesis of Ru—Re—Sn/Carbon byImpregnation (2% Ru, 4% Re, 1% Sn/Carbon JM22)

RuCl₃×H₂O (0.154 g, 40-43% Ru), HReO₄ (0.248 g of 52% solution), SnCl₄(0.095 g) were mixed and dissolved in 6.6 mL DI water. The mixed metalsolution was added dropwise under stirring to 3 g carbon (JM carbon 22)and stirred occasionally for the next 30 min and the beaker left coveredwith Parafilm for overnight. The wet catalyst was transferred on thenext day into a vacuum oven and dried under reduced pressure (40 mm Hg)at 393° K for 24 hours. The oven was cooled to under 323° K beforeremoving the catalyst. The catalyst reduction was carried following twoprocedures.

Example 28 Catalyst Reduction in Aqueous Phase (Exemplary Catalyst 5-LH)

Five hundred mg of the dried Exemplary Catalyst 5 was reduced in water(30 mL) at 523° K, 1100 psi hydrogen pressure for 3 hours in anAutoclave Engineers Autoclave constructed of 316 stainless steelmaterial. The catalyst and DI water were charged in the autoclave andthe air replace by Ar by 5 pressurized release cycles. The Ar was nextreplaced by hydrogen (200 psi) and the temperature raised to 523° K over30 min. The pressure was adjusted to 1100 psi and the suspension stirredat these settings for three hours. The autoclave was cooled to ambient,the pressure released and the catalyst washed multiple times until freeof Cl⁻ (AgNO₃ test). The sample was kept under water in sealed vialuntil use.

Example 29 Catalyst Reduction with Gaseous Hydrogen (Exemplary Catalyst5-GH)

The catalyst reduction protocol was exactly the same as the one used inExemplary Catalyst 1 except the reduction temperature was 573° K.

Example 30 Preparation of Exemplary Catalyst 6 (2% Ru, 4% Re, 1%Sn/Carbon Norit SX 1G)

The same procedure was used as for catalyst Exemplary Catalyst 5. Thetwo versions of the Catalyst, Exemplary Catalyst 6-LH and ExemplaryCatalyst 6-GH, reflect the two reduction protocols used, which was thesame as for Exemplary Catalyst 5.

Example 31 Preparation of Exemplary Catalyst 7 (2% Ru, 4% Re, 1%Sn/Carbon Norit SX 1)

The same procedure was used as for catalyst Exemplary Catalyst 5. Thetwo versions of the Catalyst, Exemplary Catalyst 7-LH and ExemplaryCatalyst 7-GH, reflect the two reduction protocols used, which was thesame as for Exemplary Catalyst 5.

Example 32 General Procedure for Hydrogenation of MAS in Batch Mode

In a representative run, a reactor flask was charged with 0.5 g of thepowdered catalyst and 3 g (22.2 mmol) of MAS was dissolved in 30 mL DIwater. The system was alternately purged with nitrogen (by fivepressurize-release cycles) and the nitrogen pressure adjusted to 200psi. The reactor was next flushed with five cycles of hydrogen and thepressure adjusted to 200 psi. The heating was started at 200° C. understirring of 250 rpm which step took an average of 20-25 min. When thetemperature stabilized at this setting, the pressure in the reactor wasadjusted to 1000 psi, stirring set to 1200 RPM and data acquisitioninitiated simultaneously. Progress of the reaction was monitored bypressure drop in the ballast reservoir and initial reactions werecontinued for a fixed reaction time of 16 hours. The reactor was cooledto ambient temperature and a sample of the solution taken for furtheranalysis by gas chromatograph.

Apparatus: HP 5890 with FID, Capillary column RTX1701, 60 m, 0.53 mminternal diameter and film thickness of 1 mkm.

Instrument conditions: Split vent: 50 ml/min, Air 300 ml/min, Hydrogen30 ml/min, Head pressure 11 psi, Injection volume: 1 mkl. Temperatureprogram: Initial 65° C., hold 5 min, ramp 10° C./min to 180° C., hold 15min. Injection and detector temp: 220° C. and 250° C.

Sample preparation: 100 mkl of sample solution was dissolved in 800 mklEtOH and 100 mkl IS solution. The IS solution was 1,3-Propanediol inethanol (10 mg/ml).

TABLE 3 Table 3. Summary of the results for reactions in the liquidphase hydrogenation of MAS over supported metal catalyst. CatalystSelectivity (% mol) Type Lot THF GBL 1,4BD 2Py SI 5%Ru/C C-6170 0.3 6.11.2 68.6 3 5%Ru/C C-6553 0.2 4.3 1.1 76.7 1.4 5%Ru/C C-7154 0.3 1.7 0.671 0.7 5%Ru/C C-7154 1.4 7.6 1.2 64 3.1 5%Pd/C C-8882 0 3.1 0 49.2 134Pd1PtBi/C C-71-55 0 9.4 0 42.2 44.5 5%Rh/C C-5322 0 2.6 0 47.2 44.3Exemplary 0.4 30.9 0 41.6 27.2 Catalyst 1 Exemplary 0 21.6 0 17.6 60.8Catalyst 1 Exemplary 0 12.1 2.2 73.3 4.3 Catalyst 5-LH Exemplary 0 15.11.4 60.4 18.3 Catalyst 6-LH Exemplary 0 13.2 1 48.7 35.9 Catalyst 7-GH T= 200° C., P = 1000 psi, Stirring rate 1200, Substrate = 6.0 g, Water =60 cc, Catalyst 1.0 g. NOTE: 2Py is 2-pyrrolidone and SI is succinimide

TABLE 4 Summary for Liquid phase hydrogenation of MAS over supported Ptcatalyst. Type Lot THF Sel GBL Sel 1.4 BDO Sel 56 5% Ru/C C-7154 1.4 7.61.2 57 5% Pt/C C-9063 0.0 11.8 0.0 58 5% Pt/C C-9090 0.0 20.4 0.0 59 5%Pt/SiAl C-9225 0.0 21.2 1.6 T = 200° C., P = 1000 psi, Stirring rate1200, Substrate = 3.0 g (22.2 mmol), Water = 30 cc, Pt/C catalyst 0.5 g(wet). Reaction time 16 hours.

Although our processes have been described in connection with specificsteps and forms thereof, it will be appreciated that a wide variety ofequivalents may be substituted for the specified elements and stepsdescribed herein without departing from the spirit and scope of thisdisclosure as described in the appended claims.

1. A process for making a hydrogenated product comprising: (a) providing a clarified fermentation broth containing an ammonium salt of succinic acid; (b) optionally adding at least one of MAS, DAS, SA, NH₃ and NH₄ ⁺ to the broth depending on pH of the broth; (c) distilling the broth to form an overhead that comprises water and optionally ammonia and a liquid bottoms that comprises MAS, at least some DAS, and at least about 20 wt % water; (d) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS; (e) separating the solid portion from the liquid portion; (f) recovering the solid portion; (g) hydrogenating the solid portion in the presence of at least one hydrogenation catalyst to produce the hydrogenated product comprising at least one of THF, GBL or BDO; and (h) recovering the hydrogenated product.
 2. The process of claim 1, further comprising purifying the second solid portion before step g.
 3. The process of claim 2, further comprising dissolving the second solid portion in a solvent to form a solution.
 4. The process of claim 1, wherein step g is conducted such that THF is recovered in a vapor phase.
 5. The process of claim 1, wherein step g is conducted such that BDO is recovered in a liquid phase.
 6. The process of claim 1, wherein the hydrogenation catalyst comprises at least one metal from Group VIII of the Periodic Table of the Elements.
 7. The process of claim 6, wherein the at least one metal consists essentially of: (i) about 0.5 to about 10% by weight ruthenium, and (ii) about 2.0 to about 20% by weight rhenium, based on total weight of the catalyst.
 8. The process of claim 7, further comprising about 0.1 to about 5.0% by weight of tin.
 9. The process of claim 4, wherein the catalyst is supported on at least one selected from the group consisting of carbon, silica, alumina, silica-alumina, silica-titania, titania, titania-alumina, barium sulfate, calcium carbonate and strontium carbonate.
 10. The process of claim 1, wherein the ammonium salt of succinic acid is selected from the group consisting of DAS and MAS. 